Method for making retainer locks



5Pt 19, 1944. o. R. scHoENRocK 2,358,350

METHOD Fon MAKING RETAINER vLocxs l Filed May 19, 1941 i v v INVENTQRPatented Sept. 19, 1944 UNITED STATES PATENT OFFICE 2,358,356 l Y lMETHOD FOR MAKING RETAINER LOCKS -Otto R. Schoenrock, Chicago, Ill.

Application May 19, 1941, Serial No. 394,063

1 Claim.

My invention relates to a method and apparatus for making retainer lockssuch as the split tapered collars or bushings used in valveassembliesyfor securing the spring retainer plate in place on the valvestem.

One of the objects of my invention is to provide an improved method bymeans of which these retainer locks may be produced rapidly andaccurately.

Further objects and advantages of the invention will be apparent fromthe description and claim.

In accordance with my invention, a metal strip or bar havingsubstantially the desired cross section of the finished' container lockis subjected to a bending and forming operation,4by means of which ahalf circle bend is formed on the end of the bar and this half circlebend is thereafter sheared from the bar to form a section of the lock.If desired, the edges of the sheared olf lock section may thereafter beground to insure the proper size of thesections. u

In the drawing inwhich my invention is illustrated:

Figure 1 is a vertical sectional View showing the bending apparatus;

Fig. 2 is a vertical sectional View showing the severing and grindingapparatus;

Fig. 3 is a view of a partially formed end of the bar;

Fig. 4 is a side view of the completely formed end of the bar;

Fig. 5 is a view showing a nished lock member severed from the bar andground;

Fig. 6 is a View from the right of Fig. 5;

Fig. 7 is a cross sectional View of the bar substantially on thelineal-'I of Fig. 4; and

Fig. 8 is a horizontal section substantially on the line 8-8 of Fig. 2.

Referring to the drawing in detail, the construction shown in Fig. 1 isfor theA purpose of forming a half circle bend in the end of the barfrom which the lock sections are formed. The construction shown in Fig.2 comprises apparatus for severing the half circle bend from the end ofthe bar to form lock sections and for grinding the edges of the locksections. i

Referring rst to Fig. 1, the apparatus here shown comprises a guideblock or frame I, a die 2 having a half circle bend forming surface, a

retractible stop 3 against which the end of thev bar 4 is pressed forpositioning it so that the right length of material will be provided forforming the bend, a vertically reciprocable punch or forming tool 5having a quadrantal conoidal forming surface 6 for forming a quartercircle bend I in the end portion of the bar as shown in Fig. 3, ahorizontally reciprocable punch 8 or forming tool having a half circleconoidal surface for pressing the end of the bar againstl the formingdie to complete a half circle bend 9 in the end of the bar, as shown inFig. 4, and a yieldable presser foot Il) which comes down on the bar 4when the forming dies are operated to hold the bar against displacementwhen the end is being bent. The stop member Bois withdrawn horizontallyin timed relation to the punch 6 so as not to obstruct its movement. The'passage II into which the bar is inserted is wideenoughA so that thebar has a slip t in this passage but'is held securely against side slip.

The construction shown in Fig. 2 comprises Va mounting block I2 having apassage I3 ,into which the bentk end of the bar is inserted after it hasbeen withdrawn from the apparatus shown in Fig. 1, a shearing edge I4 atthe inner end of this passage, a spring-pressed stop block I5 againstwhich the bent end of the bar is pressed when the bar is to be sheared,a guide passage I6 into which the sheared-oif lock sections Il areforced when Severed fron the end of the bar 4,

a reciprocating shearing blade I8 cooperating with the shearing edge I4,a rotatable grinding tool I9 operating in a recess in the block I2 forgrinding the edges of the lock sections as they are forced down theguide passage I6, and a spring presser foot 20 similar tothe presserfoot I0 shown in Fig. 1 for holding the bar 4 in positionwhen the end isbeing sheared off. The

- yielding abutment or stop-block I5 enables the half circle bend 9 tobe brought into position by the operator for shearing as shown in Fig.2, and also holds the edge of the half circle bend snugly against theface `2I of the block to insure that the shear will be made at theproper point.

In order to adjust the grinding tool I9 accurately and insure that theblock sections are ground to proper size, the bearing 22 in which thegrinder shaft 23 rotates is made axially acljustable by mounting it inan axially adjustable sleeve 24. The adjustment of this sleeve iseffected by means of a threaded connection with ment I is pressed totheright by means of a coil compression spring 30, one end of which bearson the bracket 3|, the other end of which bears against a collar 32 onthe block i5.

In operation, the end of the bar is inserted into the passageway Il inthe block shown in Fig. 1 until the end of the bar is stopped byengaging the abutment 3. The operator then puts the press in operation,causing the stop 3 to be Withdrawn, the vertically reciprocating formingtool 5 to be brought down to form a quarter circle bend in the endportion of the bar, the forming tool 5 Withdrawn, the horizontallyreciprocating forming tool 8 operated to press the end portion of thebar into the shape shown in Fig. 1, and" the horizontally reciprocatingforming tool 8 withdrawn to enable the operator to Withdraw the end ofthe bar from this :forming apparatus.

The operator then inserts the end of the bar with the half circle bendformed therein into the guide passage I3 in the apparatus shown in Fig.2; bringing the half circle bend down intothe position shown in whichthe spring pressed plunger or stop-blockvli will hold the edge of theendof the'bar snugly against the face 2|- of the block. The operatorthen puts the apparatus into operation to cause the shearing blade I8vto descend, carrying with it the spring presser foot for holding the barrmly during the shearing operation. The shearing edge shears the halfcircle bends from the bar and forces any prehave a conoidal surface fortting in a correspondingly shaped seat and the bar 4 may be providedwith internal beads 33 for tting in circumferential grooves in the valvestem.

In the claim where the expressions quarter circle, half circle andquadrantal are used, they are to be understood as broad enough to coverobvious approximations.

Further modifications will be apparent to those skilled in the art andit is desired, therefore, that the invention be limited only by thescope of the appended claim.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

A method for making a valve spring retaining lock section from astraight bar of a length sufficient to form a plurality of locksections, said bar having one flat face and having alongitudinally-extending shoulder to be 'bent for arcuate engagementwith a circumferentially-extending shoulder on the valve stem and havingits opposite face extending at an oblique angle with respect to saidflat face, comprising bending and shaping the end of the bar toV formA ahalf-circle bend with the unbent straight remaining portion extendingsubstantially tangentia-lly to the bent portion, vvithV the point oftangency substantially diametrically opposite the free end of thehalfcircle bend, and with the flat face of the bar forming a conoidalouter surface for engagement with a conoidal inner surfaceon the valvespring retainer, said opposite face forming a cylindrical surface ofengagement with the valve'stem, and thereafter severing the half-circlebend from the end of the bar substantially on a plane through the axisof the half-circle-bend and substantially at the point of tangency andsubstantially da metrical-ly opposite the freeA end of theV half-circlebend.

OTTO R. SCI-IOENROCK.

